Ms. Levy has held a number of leadership spots at the 94-year-old firm, including serving on the eight-member policy committee - the equivalent of a board of directors.

Mr. Gallopoulos, 48, will remain at Jenner & Block until midsummer before taking up his job as the defense contractor's corporate vice-president and deputy general counsel, the Tribune said. He had been managing partner at Jenner & Block for more than three years.